A regulator controller including terminals for coupling to a voltage source, an inductor and an output capacitor, and including a switching circuit and a switch control circuit. The switching circuit includes switches that toggle coupling of the inductor during switching cycles based on charge and discharge periods. The switch control sets a duration of the charging period based on the input voltage and sets duration of the discharging period based on a difference between the input and output voltages. Multiple output terminals allow coupling to different load types, in which the output terminals may be temporarily coupled together to handle bursted loads. Thus, an output store capacitor may be coupled to handle a bursted load, and then decoupled for charging. Comparator circuits enable/inhibit switching based on input and output conditions. The regulator controller maximizes utilization of weak power sources while sufficiently handling typical load profiles.